Diamond Database is a comprehensive platform designed to offer detailed insights on different diamond shapes and sizes. It has been developed to answer all questions pertaining to size, particularly for those who may find it challenging to visualize sizes stated in mm or carats.

A unique feature of the Diamond Database is its diamond size simulator. It enables users to compare real diamond sizes on a scaled ring and finger, facilitating a better understanding of how a diamond of a particular carat size would appear when worn. This feature can be incredibly beneficial for those looking to buy diamond rings but are unsure about the size they should go for.

The platform is highly informative. It provides a wealth of helpful information including size evaluation guides and comprehensive buying walkthroughs. These resources are geared towards assisting users at different stages of diamond buying or studying, be it for purchasing engagement rings, gemologists seeking further knowledge, or simply for individuals who are interested in learning about diamonds.

Moreover, the Diamond Database allows users to explore and compare different diamond shapes: from the classic and highly popular Round Brilliant designed for maximum sparkle to the contemporary Princess cut with square lines and sharp corners. Users can also examine other shapes such as Emerald, Asscher, Radiant, Cushion, Oval, Pear, Marquise, Heart, and Trillion, providing a broad perspective for comparisons and choices.

In terms of usability, the interface of Diamond Database is user-friendly, making navigation through different sections an easy task. Whether someone wants to jump straight into the size simulator or wishes to explore various diamond shapes beforehand, the platform is set up to accommodate the diverse needs of its users.

Verdict: Diamond Database is a valuable tool offering a comprehensive view of diamond shapes and sizes. Its simulator and various guides provide support to users at different stages of diamond exploration, whether for purchase or knowledge acquisition. Whether a novice or a professional in the field of gemology, the platform is designed to cater to a wide audience.